Cutting tool



May 5, 1953' E. c. HOWELL CUTTING TOOL Filed Oct. 27, 1947 IN V EN TOR.EVERETT G. HOWELL Patented May 5, 1953 UNITED STATES TENT OFFICE-"CUTTING TOOL Everett 0. Howell, Riverside, Calif. Application October27, 1947, Serial No. 782,278

-14 Claims. 1

"The present invention relates to cuttersespecially useful in drillinghorizontal holes throu h the cuttings are'not properly and efficientlydisposed of. Wh'fle a bit may operate satisfactorily when relativelynew, the :bit "may become rusty or corroded, in which case the rustimpedes the movement of cuttings past the bit in which case the cuttingsback up again t the cutters .t'i tend and to sometimes restrict theirnormal clesired rotary movement. It is therefore an object of the.present'invention to provide an improvedcutting bit arran ed to assurethe unimpeded mocment of cuttings from the cutter elements when the bitis new and also after it has been oneratei for a considerable period oftimewherefn it mi'rht otherwise corrode or rust. To this end, an im-"portant feature of the present invention i the provision of flutes inthe body oi the drill bit which isxoftnonferrous metal. Not ony does thenonferrous metal not corrode or rust. but is also of such nature as toallow easy casting of the flutes or helical grooves therein.

An obect oi'the present invention is to provide an improved cutterarrangement of the type specified arranged to reduce abra ion to aminimum'with :a cutter of maximum strength.

Another object of the present invention is to provide an improved cutterstructure of the type specified having rotary cutters thereon in spiral"flutes arranged-on the periphery-of the body, the flutes being arrangedto strengthen the body of thebit or cutter, to carry cuttings back fromsuch cutters mounted thereon with water of pressure in'the range foundin households,and to feed the tool into the soil when ahorizcntal holeis being drilled without the support ng weight of a string as is presentwhen drilling a vertical hole.

Still another object of the present invention is to provide an improvedcutting tool or hit in which the flutes remain polished for bestperformance, the bit being for that purpose of nonferrous metal on whichthe flutes may be formed 'in a castingoperation. I

'ticularity in the appended claims.

Still another object of the present invention is to provide an improvedbit having rotary cutters thereon with water apertures disposed in thebit to direct a stream of water onto the rotary cutters in a mostadvantageous manner.

Still a further object of the present invention is to provide animproved cutter through which water is fed in a cutting operation withthe elements thereof being coupled in a novel manner to form a silt trapto thereby obviate possibility of the waterpath becoming clogged.

Still a further object of the present invention is to provide animproved cutter structure having rotary cutter elements thereon andthrough which water is projected in a novel manner against the rotarycutters and also against the uncut portion of the bore whereby theentering water serves not only in conditionng the bore for. subsequententrance of the cutters but also serves to maintain the cutter elementsclean.

Still another object of -the present invention is to provide an improvedbit arranged to bore a'hole through dirt,sand-and rock more efficientlyand with less likelihood of trouble than is present'y possible.

A still further object of the present invention is to provide animproved drill bit which operates efficiently and satisfactorily withwater passing 'therethrovgh at a pressure in the rangeof '20 lb.

to 100 lb. per sqjinch.

The features of the present invention which are believed to be novel areset 'forth with par- This invention itself, both as to its organizationand manner of operation, together with further objects and advantagesthereof, "may be best understood by reference to the followingdescription taken in on the line 3-3 of "Figure 2.

While I have shown both a cutter or drill bit and a reamer on the drillstring shown in Figure 1, the cutter or drill bit andreamer, both ofwhich embody features of the present invention, may be usedindependently of one another.

For example, the cutter only may be'mounted .onthe .drijll string to outa'holefan'd then subsequently the cutter withdrawn and the reamer on aseparate drill string may be passed through the hole drilled by thecutter or bit.

The drill bit is of nonferrous metal which may be easily cast in theprecise shape shown in Figure 1 with the flutes I I and I2 on the outersurface thereof, terminating at the front end of the reduced crosssection, and with a main water channel l3, branching off into waterchannels l4, I5 and 16 therein.

The back end of the bit has an external screw threaded portion I1thereon, together with an annular flange [8 of reduced diameter for apurpose described later.

Rotary cutters 20 and 2|, respectively, are mounted on the bit I in theflutes H and 12, respectively. The manner in which these cutters aremounted is shown in detail in Figure 3 wherein the cutter 20 isrotatably mounted on the axle 24 having an external screw threaded end25 threaded into the body of the bit It with lock washer means 26interposed therebetween to prevent loosening and rotation of the axle 24on the body it.

The water channels l3 and I extend centrally and axially of the drillbit l0 so as to cause the projection of a stream of water into the borebetween the two cutters 20 and 2| while the other two channels l4 and [6are arranged to project a stream of water against the back faces of therotary cutter elements 20 and 2! to thereby prevent the accumulation orbacking of cuttings between such cutters and the bit body I0. For thispurpose, as shown in Figure 3, the peripheral cutting edges of thecutters 20 are spaced from the drill bit body It by the inner enlargedportion of the cutter, as well as by the lock washer means 26.

The reamer 30 is of substantially the same construction as the drill bit[0 except that its rotary cutter elements 3! and 32 are at a greaterdistance from the rotational axis of the drill string, and the reamer isopen at both ends on which are provided external threaded portions forthe passage of water therethrough. The individual cutters 3| and 32 aremounted centrally and at the lowest point in the flutes at 33, 34,respectively, in the same manner as are the cutters 20 and 2|; and, inthe same fashion, water channels 35 serve to direct a stream of wateragainst the other side of the cutters 3! and 32.

The drill bit and reamer 30 may be joined together by conventional typeof coupling til with the tapered inner flange 48 along the drill bodyentering the hollow portion of the reamer 30 to thereby provide a siltand dirt tra at 4|. The other end of the reamer 30 may be coupled to arod or tube 50 of the stem to which rotary movement is imparted in aconventional manner.

It is noted that drill bit it) and reamer 30 each have a number ofspiral flutes thereon corresponding to the number of cutters mountedthereon, the rotational axis of each cutter passing centrally throughthe lowest point of the flute.

It is noted that the rotary cutters 20 and 2! have their planes ofrotation inclined forwardly in the direction of the drilling. This isalso true of the cutters 3| and 32 on the reamer 30, but the reamercutters 3| and 32 are inclined at substantially the same inclination.

While I have shown two cutters and two flutes, it is within the provinceof the present invention to use more than two cutter wheels and in suchcase preferably there are as many flutes as there are cutting wheels.Also, in such case there is a water channel behind each one of suchcutters to '4 project a stream of water against back face of each ofsuch cutters.

It is apparent in the structure described that the abrasion on the drillbit or the reamer, as the case may be, is reduced to a minimum by theprovision of the flutes which are of rust-proof, non-corrosive,non-ferrous material. The flutes serve also to impart strength to thebit or drill. In such case, satisfactory cutting may be obtained withlow water pressure in the range of 20 lb. to lb. per sq. inch.

While I prefer to produce the body of the drill bit and reamer bycasting operation because of the simplicity and inexpensiveness, theseelements may likewise be formed by machining operations.

While the particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from thisinvention in its broader aspects and, therefore, the aim in the appendedclaims is to cover all such changes and modifications as fall within thetrue spirit and scope of this invention.

I claim:

1. A drill bit of the character described, comprising an elongatedtapered solid body of nonferrous material which does not corrode or rustand which allows easy casting, said material having helical grooves onits outer surface, rotary cutters mounted thereon with the axis ofrotation of each cutter passing respectively through each one of saidhelical grooves at the forward end of the bit, with a portion thereofextendin beyond said forward end and with its rotational axis at anacute angle with respect to the axis of the drill, the diameter of eachof said cutters being greater than the width of the correspondinggroove, with said cutters overhanging the forward tip of said body tominimize abrasion of said tip and to assure better cleaning of the spacebetween said cutters and said body, said body having a water channelextending therethrough arranged to project a stream of water against theinside surfaces of said cutter, and a conduit at the tip of said taperedbody in communication with said Water channel arranged to direct astream of water forwardly and along the axis of said body.

2. A reamer of the character described having a longitudinal openingtherethrough for the passage of fluid, said reamer being of nonferrousmaterial which does not corrode or rust and which allows easy casting,said material having helical grooves on its outer surface, andcorresponding rotary cutters mounted thereon with the rotational axis ofeach cutter passing centrally in each one of said helical grooves, eachof said rotary cutters having a diameter greater than the correspondinggroove, with said cutters overhanging the forward tip of said body tominimize abrasion of said tip and to assure better cleaning of the spacebetween said cutters and said body, lateral openings in communicationwith said longitudinal opening and terminating adjacent said cutters todirect the flow of fluid onto said cutters.

3. In a drill string of the character described, a drill bit releasablyconnected to a coupling, and a reamer releasably joined to saidcoupling, said drill bit and said reamer each being of nonferrousmaterial which does not corrode or rust and which allows easy casting,said material having helical grooves on their outer surfaces,corresponding cutters mounted thereon with the rotational axis of eachcutter passing through each one of said helical grooves on said drillbit and said reamer, the diameter of the cutters on said drill bit beinggreater than the width of the corresponding groove, with said cuttersoverhanging the forward tip of said drill bit, to minimize ab asion ofsaid tip and to assure better cleaning of the space between said cuttersand said drill bit, said coupling being internally threaded and havingan internal bore, said drill bit having an externally threaded portionarranged for cooperation with the internally threaded coupling, saidexternally threaded portion of said bit having extending therefrom anannular flange of diameter smaller than the diameter of the bore of saidcoupling and positioned to project therein when said bit is threadedinto said coupling, said reamer having an externally threaded portionfor cooperation with the threaded coupling, said reamer having a waterchannel extending centrally therethrough and said water channel being ofsize larger than the diameter of said flange to receive said flange whensaid bit and reamer are each screwed into said coupling, with the spacebetween the ends of the threaded portions of said bit and said reamerand the adjacent in- 6 ternal Wall of the coupling forming a dirt andsilt trap.

4. The arrangement set forth in claim 3 in which each one of saidcutters comprises a centrally apertured disc, the rim of the disc beingof a thickness less than the thickness of its central portion, and theouter edge of the disc being bevelled inwardly towards the correspondingdrill bit and reamer, respectively.

EVERETT C. HOWELL.

References Cited in the file of this patent UNITED STATES PATENTS

